The background of the invention will be discussed in two parts.
1. Field of the Invention
The present invention relates to portable, high liquid volume, back-carried sprayers of pressurized liquids, and more particularly to such a sprayer which includes a battery pack and motorized pump arrangement.
2. Description of the Prior Art
Sprayers intended for the dispensing of liquid disinfectants, insecticides, fertilizers, pest exterminating liquids and other residential or agricultural-type treatment liquids normally contain a reservoir or tank for carrying of the liquids therein. Such sprayers are normally designed for portability, such as carrying by hand, or on the back, by use of webbing or straps connected to the sprayer in such a manner that the straps enable the sprayer to be carried by the shoulders and back of the user. Such sprayers normally include a manually operated lever actuated pump which is actuable by the user for dispensing the liquids through a hose. In some such sprayers, to avoid a need for continually operating the lever while dispensing liquids, an internal pressure tank is employed, whereby the internal tank may be placed under pressure by actuation of the lever with, or without, dispensing of fluids. In such sprayers, liquid discharge flows more continuously as a conseqeunce of the pressure. One such pressurized garden sprayer is shown and described in U.S. Pat. No. 2,162,057, entitled "Knapsack Sprayer", issued to H. Brandt et al on June 13, 1939. Other manually operated portable garden sprayers are shown in U.S. Pat. Nos. 2,192,256, entitled "Sprayer With Agitator", issued to Brandt on Mar. 5, 1940; and 3,966,092, entitled "Manually Operated ManPortable Sprayer", issued to Ballu on June 29, 1976.
Some liquid sprayers, and even some dusters for discharging liquids or particulate matter have been developed with electrically operated pump or blower arrangements. The following patents exemplify the prior art relating to such aparatus: U.S. Pat. Nos. 2,429,773, entitled "Dusting Apparatus", issued Oct. 28, 1947 to Root; 2,881,555, entitled "Crop Duster", issued Apr. 14, 1959 to Atkinson, Sr., et al; 3,386,622, entitled "Portable, Self-Contained Electrical Pumping Device", issued June 4, 1968 to Cox et al; 3,421,697, entitled "Spraying Equipment", issued Jan. 14, 1969 to Marks; and 3,901,449, entitled "Cordless Electric Sprayer", issued Aug. 26, 1975 to Bochmann. Such prior art sprayers and dusters provide motors for driving pumps and blowers with little regard to the placement of the heavier parts of the apparatus, thus rendering the carrying of such apparatus uncomfortable and potentially hazardous. Furthermore, although in most instance, such apparatus include some form of base for support, when partially full and placed on the ground, the center of gravity of the apparatus is unduly high, thus providing instability at rest.
Exemplary of such prior art motor operated apparatus is U.S. Pat. No. 3,199,785, entitled "Portable Spraying Device and Support", issued Aug. 10, 1965 to Schmierer. The sprayer is gasoline motor operated and includes an integrally formed back support and receptacle with the support having integrally formed provision for attachment of the gasoline engine thereto. Attached to the support, below the engine arrangement, is a frame formed of metallic tubing, bent at an angle to serve as a stand to support the apparatus on a surface. As part of the apparatus an attempt is made to provide stability by placing the center of gravity of the engine inwardly of the limits of the stand. However, with such an arrangement with the receptacle at the very top and the engine mounted generally centrally relative to the vertical standing position, the overall center of gravity is high, thus creating a tendency to readily tip if impacted from the front or rear. The container and support of the '785 patent are specifically formed for the engine utilized, and they cannot be used with any other existing apparatus.
High volume agricultural sprayers in use today are mainly manual or gasoline engine powered. With gasoline engines as a source of power, prior art apparatus have limitations on location and timing of use. Such gasoline engines are limited in usage to outdoor locations, and in most instances, because of noise pollution, are limited in use to certain times of the day. Such sprayers cannot be used, for example, indoors, such as in a hospital, or the like, to spray disinfectants.
It is accordingly an object of the present invention to provide an agricultural, insecticide, or disinfectant sprayer that avoids or minimizes the above-mentioned disadvantages.